The current modular automation controller offers a variety of discrete input and output (I/O) modules, such as DC Input, DC Output, AC Input, AC Output, etc. However a module offers only one type of functionality: input or output, and only one type of electrical interface for that functionality: such as DC or AC. For example an input module will provide only input, and output module will provide only output functionality, and all the points of a module will have same electrical characteristics. This many times forces users to buy more hardware than necessary. For example if a controller offers 32-point modules and a user requires only, say, 1 input and 1 output, the user would need to buy two modules: one input module and one output module, even though physically one module would have served the purpose. In addition, some times need for additional I/O may necessitate going to a larger controller rack or adding a remote rack, though many I/O points in the existing rack may be unused because of wrong functionality type.
Similar situation exist with respect to electrical interface. A module offers all the discrete point of same electrical type. For example a 32 point DC output module will have same electrical characteristics for all the 32 points. If a user needs one DC output and one AC output, the user needs to buy a two modules.
Current invention presents combination I/O modules that offer input and output functionality on the same module, and modules with more than one type of electrical interface to field devices on the same module. By offering judicious combinations of various input and output type, the invention allows users select optimal hardware for their controller.